This patch adds support for touchpad found on Dell XT2. It's a dual device
with device ID: 73, 00, 14, that comply with "ALPS_PROTO_V2".
Signed-off-by: NYunkang Tang <yunkang.tang@cn.alps.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>